<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        /* 100+10 */
        #home .app {

        }

        /* 100 + 10 + 1 + 1 */
        #home .app div img{

        }
    </style>
</head>
<body>
    <script>
        var a = 2; // 0010  => 0000
        var b = 4; // 0100  1&1 = 1
        console.log(a & b); // 0
        console.log(a | b); // 0110   6
        console.log(a >> 2) // 向右移动2位

        console.log(a<<2) // 1000 8
    </script>
</body>
</html>